1/*
2 * isl29125.c - Support for Intersil ISL29125 RGB light sensor
3 *
4 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
5 *
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License.  See the file COPYING in the main
8 * directory of this archive for more details.
9 *
10 * RGB light sensor with 16-bit channels for red, green, blue);
11 * 7-bit I2C slave address 0x44
12 *
13 * TODO: interrupt support, IR compensation, thresholds, 12bit
14 */
15
16#include <linux/module.h>
17#include <linux/i2c.h>
18#include <linux/delay.h>
19#include <linux/pm.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23#include <linux/iio/trigger_consumer.h>
24#include <linux/iio/buffer.h>
25#include <linux/iio/triggered_buffer.h>
26
27#define ISL29125_DRV_NAME "isl29125"
28
29#define ISL29125_DEVICE_ID 0x00
30#define ISL29125_CONF1 0x01
31#define ISL29125_CONF2 0x02
32#define ISL29125_CONF3 0x03
33#define ISL29125_STATUS 0x08
34#define ISL29125_GREEN_DATA 0x09
35#define ISL29125_RED_DATA 0x0b
36#define ISL29125_BLUE_DATA 0x0d
37
38#define ISL29125_ID 0x7d
39
40#define ISL29125_MODE_MASK GENMASK(2, 0)
41#define ISL29125_MODE_PD 0x0
42#define ISL29125_MODE_G 0x1
43#define ISL29125_MODE_R 0x2
44#define ISL29125_MODE_B 0x3
45#define ISL29125_MODE_RGB 0x5
46
47#define ISL29125_MODE_RANGE BIT(3)
48
49#define ISL29125_STATUS_CONV BIT(1)
50
51struct isl29125_data {
52	struct i2c_client *client;
53	struct mutex lock;
54	u8 conf1;
55	u16 buffer[8]; /* 3x 16-bit, padding, 8 bytes timestamp */
56};
57
58#define ISL29125_CHANNEL(_color, _si) { \
59	.type = IIO_INTENSITY, \
60	.modified = 1, \
61	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
62	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
63	.channel2 = IIO_MOD_LIGHT_##_color, \
64	.scan_index = _si, \
65	.scan_type = { \
66		.sign = 'u', \
67		.realbits = 16, \
68		.storagebits = 16, \
69		.endianness = IIO_CPU, \
70	}, \
71}
72
73static const struct iio_chan_spec isl29125_channels[] = {
74	ISL29125_CHANNEL(GREEN, 0),
75	ISL29125_CHANNEL(RED, 1),
76	ISL29125_CHANNEL(BLUE, 2),
77	IIO_CHAN_SOFT_TIMESTAMP(3),
78};
79
80static const struct {
81	u8 mode, data;
82} isl29125_regs[] = {
83	{ISL29125_MODE_G, ISL29125_GREEN_DATA},
84	{ISL29125_MODE_R, ISL29125_RED_DATA},
85	{ISL29125_MODE_B, ISL29125_BLUE_DATA},
86};
87
88static int isl29125_read_data(struct isl29125_data *data, int si)
89{
90	int tries = 5;
91	int ret;
92
93	ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
94		data->conf1 | isl29125_regs[si].mode);
95	if (ret < 0)
96		return ret;
97
98	msleep(101);
99
100	while (tries--) {
101		ret = i2c_smbus_read_byte_data(data->client, ISL29125_STATUS);
102		if (ret < 0)
103			goto fail;
104		if (ret & ISL29125_STATUS_CONV)
105			break;
106		msleep(20);
107	}
108
109	if (tries < 0) {
110		dev_err(&data->client->dev, "data not ready\n");
111		ret = -EIO;
112		goto fail;
113	}
114
115	ret = i2c_smbus_read_word_data(data->client, isl29125_regs[si].data);
116
117fail:
118	i2c_smbus_write_byte_data(data->client, ISL29125_CONF1, data->conf1);
119	return ret;
120}
121
122static int isl29125_read_raw(struct iio_dev *indio_dev,
123			   struct iio_chan_spec const *chan,
124			   int *val, int *val2, long mask)
125{
126	struct isl29125_data *data = iio_priv(indio_dev);
127	int ret;
128
129	switch (mask) {
130	case IIO_CHAN_INFO_RAW:
131		if (iio_buffer_enabled(indio_dev))
132			return -EBUSY;
133		mutex_lock(&data->lock);
134		ret = isl29125_read_data(data, chan->scan_index);
135		mutex_unlock(&data->lock);
136		if (ret < 0)
137			return ret;
138		*val = ret;
139		return IIO_VAL_INT;
140	case IIO_CHAN_INFO_SCALE:
141		*val = 0;
142		if (data->conf1 & ISL29125_MODE_RANGE)
143			*val2 = 152590; /* 10k lux full range */
144		else
145			*val2 = 5722; /* 375 lux full range */
146		return IIO_VAL_INT_PLUS_MICRO;
147	}
148	return -EINVAL;
149}
150
151static int isl29125_write_raw(struct iio_dev *indio_dev,
152			       struct iio_chan_spec const *chan,
153			       int val, int val2, long mask)
154{
155	struct isl29125_data *data = iio_priv(indio_dev);
156
157	switch (mask) {
158	case IIO_CHAN_INFO_SCALE:
159		if (val != 0)
160			return -EINVAL;
161		if (val2 == 152590)
162			data->conf1 |= ISL29125_MODE_RANGE;
163		else if (val2 == 5722)
164			data->conf1 &= ~ISL29125_MODE_RANGE;
165		else
166			return -EINVAL;
167		return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
168			data->conf1);
169	default:
170		return -EINVAL;
171	}
172}
173
174static irqreturn_t isl29125_trigger_handler(int irq, void *p)
175{
176	struct iio_poll_func *pf = p;
177	struct iio_dev *indio_dev = pf->indio_dev;
178	struct isl29125_data *data = iio_priv(indio_dev);
179	int i, j = 0;
180
181	for_each_set_bit(i, indio_dev->active_scan_mask,
182		indio_dev->masklength) {
183		int ret = i2c_smbus_read_word_data(data->client,
184			isl29125_regs[i].data);
185		if (ret < 0)
186			goto done;
187
188		data->buffer[j++] = ret;
189	}
190
191	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
192		iio_get_time_ns());
193
194done:
195	iio_trigger_notify_done(indio_dev->trig);
196
197	return IRQ_HANDLED;
198}
199
200static const struct iio_info isl29125_info = {
201	.read_raw = isl29125_read_raw,
202	.write_raw = isl29125_write_raw,
203	.driver_module = THIS_MODULE,
204};
205
206static int isl29125_buffer_preenable(struct iio_dev *indio_dev)
207{
208	struct isl29125_data *data = iio_priv(indio_dev);
209
210	data->conf1 |= ISL29125_MODE_RGB;
211	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
212		data->conf1);
213}
214
215static int isl29125_buffer_predisable(struct iio_dev *indio_dev)
216{
217	struct isl29125_data *data = iio_priv(indio_dev);
218	int ret;
219
220	ret = iio_triggered_buffer_predisable(indio_dev);
221	if (ret < 0)
222		return ret;
223
224	data->conf1 &= ~ISL29125_MODE_MASK;
225	data->conf1 |= ISL29125_MODE_PD;
226	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
227		data->conf1);
228}
229
230static const struct iio_buffer_setup_ops isl29125_buffer_setup_ops = {
231	.preenable = isl29125_buffer_preenable,
232	.postenable = &iio_triggered_buffer_postenable,
233	.predisable = isl29125_buffer_predisable,
234};
235
236static int isl29125_probe(struct i2c_client *client,
237			   const struct i2c_device_id *id)
238{
239	struct isl29125_data *data;
240	struct iio_dev *indio_dev;
241	int ret;
242
243	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
244	if (indio_dev == NULL)
245		return -ENOMEM;
246
247	data = iio_priv(indio_dev);
248	i2c_set_clientdata(client, indio_dev);
249	data->client = client;
250	mutex_init(&data->lock);
251
252	indio_dev->dev.parent = &client->dev;
253	indio_dev->info = &isl29125_info;
254	indio_dev->name = ISL29125_DRV_NAME;
255	indio_dev->channels = isl29125_channels;
256	indio_dev->num_channels = ARRAY_SIZE(isl29125_channels);
257	indio_dev->modes = INDIO_DIRECT_MODE;
258
259	ret = i2c_smbus_read_byte_data(data->client, ISL29125_DEVICE_ID);
260	if (ret < 0)
261		return ret;
262	if (ret != ISL29125_ID)
263		return -ENODEV;
264
265	data->conf1 = ISL29125_MODE_PD | ISL29125_MODE_RANGE;
266	ret = i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
267		data->conf1);
268	if (ret < 0)
269		return ret;
270
271	ret = i2c_smbus_write_byte_data(data->client, ISL29125_STATUS, 0);
272	if (ret < 0)
273		return ret;
274
275	ret = iio_triggered_buffer_setup(indio_dev, NULL,
276		isl29125_trigger_handler, &isl29125_buffer_setup_ops);
277	if (ret < 0)
278		return ret;
279
280	ret = iio_device_register(indio_dev);
281	if (ret < 0)
282		goto buffer_cleanup;
283
284	return 0;
285
286buffer_cleanup:
287	iio_triggered_buffer_cleanup(indio_dev);
288	return ret;
289}
290
291static int isl29125_powerdown(struct isl29125_data *data)
292{
293	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
294		(data->conf1 & ~ISL29125_MODE_MASK) | ISL29125_MODE_PD);
295}
296
297static int isl29125_remove(struct i2c_client *client)
298{
299	struct iio_dev *indio_dev = i2c_get_clientdata(client);
300
301	iio_device_unregister(indio_dev);
302	iio_triggered_buffer_cleanup(indio_dev);
303	isl29125_powerdown(iio_priv(indio_dev));
304
305	return 0;
306}
307
308#ifdef CONFIG_PM_SLEEP
309static int isl29125_suspend(struct device *dev)
310{
311	struct isl29125_data *data = iio_priv(i2c_get_clientdata(
312		to_i2c_client(dev)));
313	return isl29125_powerdown(data);
314}
315
316static int isl29125_resume(struct device *dev)
317{
318	struct isl29125_data *data = iio_priv(i2c_get_clientdata(
319		to_i2c_client(dev)));
320	return i2c_smbus_write_byte_data(data->client, ISL29125_CONF1,
321		data->conf1);
322}
323#endif
324
325static SIMPLE_DEV_PM_OPS(isl29125_pm_ops, isl29125_suspend, isl29125_resume);
326
327static const struct i2c_device_id isl29125_id[] = {
328	{ "isl29125", 0 },
329	{ }
330};
331MODULE_DEVICE_TABLE(i2c, isl29125_id);
332
333static struct i2c_driver isl29125_driver = {
334	.driver = {
335		.name	= ISL29125_DRV_NAME,
336		.pm	= &isl29125_pm_ops,
337		.owner	= THIS_MODULE,
338	},
339	.probe		= isl29125_probe,
340	.remove		= isl29125_remove,
341	.id_table	= isl29125_id,
342};
343module_i2c_driver(isl29125_driver);
344
345MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
346MODULE_DESCRIPTION("ISL29125 RGB light sensor driver");
347MODULE_LICENSE("GPL");
348